Use size_t instead of unsigned int

Addresses follow-up review on commit fc3c769.

Test: m checkbuild
Change-Id: I79cd341c425ebe27cc66584540398fc98e94be50
diff --git a/bpfloader/BpfLoader.cpp b/bpfloader/BpfLoader.cpp
index ff63564..e173e67 100644
--- a/bpfloader/BpfLoader.cpp
+++ b/bpfloader/BpfLoader.cpp
@@ -52,14 +52,14 @@
 #define BPF_PROG_PATH "/system/etc/bpf"
 #define BPF_PROG_SRC BPF_PROG_PATH "/bpf_kern.o"
 
-#define CLEANANDEXIT(ret, mapPatterns)                           \
-    do {                                                         \
-        for (unsigned long i = 0; i < mapPatterns.size(); i++) { \
-            if (mapPatterns[i].fd > -1) {                        \
-                close(mapPatterns[i].fd);                        \
-            }                                                    \
-        }                                                        \
-        return ret;                                              \
+#define CLEANANDEXIT(ret, mapPatterns)                    \
+    do {                                                  \
+        for (size_t i = 0; i < mapPatterns.size(); i++) { \
+            if (mapPatterns[i].fd > -1) {                 \
+                close(mapPatterns[i].fd);                 \
+            }                                             \
+        }                                                 \
+        return ret;                                       \
     } while (0)
 
 using android::bpf::BpfMapInfo;
@@ -76,7 +76,7 @@
         BpfMapInfo(CONFIGURATION_MAP, CONFIGURATION_MAP_PATH),
         BpfMapInfo(UID_OWNER_MAP, UID_OWNER_MAP_PATH),
     };
-    for (unsigned long i = 0; i < mapPatterns.size(); i++) {
+    for (size_t i = 0; i < mapPatterns.size(); i++) {
         if (mapPatterns[i].fd < 0) {
             ALOGE("Rerieve Map from %s failed: %d", mapPatterns[i].path.c_str(), mapPatterns[i].fd);
             CLEANANDEXIT(-1, mapPatterns);